In completions that span multiple zones, an array of screens is frequently positioned in each of the zones. The zones are typically isolated with packers and are individually fractured and gravel packed generally in a downhole to uphole direction. In the past a given zone could be long enough to warrant using multiple screen sections. Typically, each of these screen sections had a base pipe under the screen material and a valve, typically a sliding sleeve, associated with each screen section. The annular space between the screen material and the base pipe for each screen section was sealed at opposed ends on a given screen section and the only access into the base pipe for flow of production to the surface was the sliding sleeve valve in each of the sections.
This configuration required multiple sliding sleeve valves that had to be operated and created issues of flow distribution within a given zone. This lead to the concept of connecting the annular spaces between adjacent screens through the use of ported couplings. This, in essence, made the various standalone screens function more akin to a single screen. Several US Patents illustrate the jumper path between the annular flow areas between the screen and its respective base pipe, and they are U.S. Pat. Nos. 6,405,800 and 7,048,061. U.S. Pat. No. 6,752,207 shows a way to hook together shunt tubes outside of screen sections through couplings. U.S. Pat. Nos. 6,464,006 and 5,865,251 show gravel packing systems that use screens with sliding sleeves that can close them off, such as when a wash pipe with a shifting tool is pulled out of the screen assembly. U.S. Pat. No. 7,451,816 uses base pipe openings in screens that can be covered as an aide to gravel deposition in a surrounding annulus.
Despite the various designs that connected annular spaces in screens through jumper lines and couplings between the screen sections, the base pipes continued to hold the sliding sleeves so that there was still as many sliding sleeves to operate as before to fully open a zone. The other lingering issue of the prior designs with the location of the sliding sleeves inside the base pipe flow bore and directly under the screen assembly that covered the base pipe was that the resulting flow area or drift dimension of the screen section was diminished which limited the size of tools that could get through a given screen as well as created flow constrictions that could limit production or require the use of artificial lift techniques that consume additional power and create other costs for procurement and installation.
The present invention addresses these issues and others by placing the access valves in the couplings where there is generally more room to locate the valve structure because the outside dimension of the coupling does not have the overlying screen structure on it. Additionally a single valve can connect some to all of the screens in a given zone so as to make access to entire zone for flow or for isolation go that much faster. The equipment cost is reduced as well as the risk of a malfunction. The flow is not constricted with the valve assembly located in a coupling. The passages among the screen sections that encompass the couplings can also be the location for a variety of instruments that can sense well conditions and flow through the screen sections to name a few examples. These and other aspects of the present invention will become more apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while understanding that the full scope of the invention is determined by the appended claims.